<template>
    <div class="component-upload-image">
        <el-upload
            ref="imageUpload"
            :action="uploadImgUrl"
            :before-upload="handleBeforeUpload"
            :class="{hide: this.fileList.length >= this.limit}"
            :file-list="fileList"
            :headers="headers"
            :limit="limit"
            :on-error="handleUploadError"
            :on-exceed="handleExceed"
            :on-preview="handlePictureCardPreview"
            :on-remove="handleDelete"
            :on-success="handleUploadSuccess"
            :show-file-list="true"
            list-type="picture-card"
            multiple
        >
            <i class="el-icon-plus"></i>
        </el-upload>

        <!-- 上传提示 -->
        <div v-if="showTip" slot="tip" class="el-upload__tip">
            请上传
            <template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template>
            <template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>
            的文件
        </div>

        <el-dialog
            :visible.sync="dialogVisible"
            append-to-body
            title="预览"
            width="800"
        >
            <img
                :src="dialogImageUrl"
                style="display: block; max-width: 100%; margin: 0 auto"
            />
        </el-dialog>
    </div>
</template>

<script>
import {getToken} from "@/utils/auth";
import {delOss, listByIds} from "@/api/system/oss";

export default {
    props: {
        value: [String, Object, Array],
        // 图片数量限制
        limit: {
            type: Number,
            default: 5,
        },
        // 大小限制(MB)
        fileSize: {
            type: Number,
            default: 5,
        },
        // 文件类型, 例如['png', 'jpg', 'jpeg']
        fileType: {
            type: Array,
            default: () => ["png", "jpg", "jpeg"],
        },
        // 是否显示提示
        isShowTip: {
            type: Boolean,
            default: true
        }
    },
    data () {
        return {
            number: 0,
            uploadList: [],
            dialogImageUrl: "",
            dialogVisible: false,
            hideUpload: false,
            uploadImgUrl: window.urlConfig.baseURL + "/resource/oss/upload", // 上传的图片服务器地址
            headers: {
                Authorization: "Bearer " + getToken(),
            },
            fileList: []
        };
    },
    watch: {
        value: {
            async handler (val) {
                if (val) {
                    // 首先将值转为数组
                    let list;
                    if (Array.isArray(val)) {
                        list = val;
                    } else {
                        await listByIds(val).then(res => {
                            list = res.data;
                        })
                    }
                    // 然后将数组转为对象数组
                    this.fileList = list.map(item => {
                        // 此处name使用ossId 防止删除出现重名
                        item = {name: item.ossId, url: item.url, ossId: item.ossId};
                        return item;
                    });
                } else {
                    this.fileList = [];
                    return [];
                }
            },
            deep: true,
            immediate: true
        }
    },
    computed: {
        // 是否显示提示
        showTip () {
            return this.isShowTip && (this.fileType || this.fileSize);
        },
    },
    methods: {
        // 上传前loading加载
        handleBeforeUpload (file) {
            let isImg = false;
            if (this.fileType.length) {
                let fileExtension = "";
                if (file.name.lastIndexOf(".") > -1) {
                    fileExtension = file.name.slice(file.name.lastIndexOf(".") + 1);
                }
                isImg = this.fileType.some(type => {
                    if (file.type.indexOf(type) > -1) return true;
                    if (fileExtension && fileExtension.indexOf(type) > -1) return true;
                    return false;
                });
            } else {
                isImg = file.type.indexOf("image") > -1;
            }

            if (!isImg) {
                this.$modal.msgError(`文件格式不正确, 请上传${this.fileType.join("/")}图片格式文件!`);
                return false;
            }
            if (this.fileSize) {
                const isLt = file.size / 1024 / 1024 < this.fileSize;
                if (!isLt) {
                    this.$modal.msgError(`上传头像图片大小不能超过 ${this.fileSize} MB!`);
                    return false;
                }
            }
            this.$modal.loading("正在上传图片，请稍候...");
            this.number++;
        },
        // 文件个数超出
        handleExceed () {
            this.$modal.msgError(`上传文件数量不能超过 ${this.limit} 个!`);
        },
        // 上传成功回调
        handleUploadSuccess (res, file) {
            if (res.code === 200) {
                this.uploadList.push({name: res.data.fileName, url: res.data.url, ossId: res.data.ossId});
                this.uploadedSuccessfully();
            } else {
                this.number--;
                this.$modal.closeLoading();
                this.$modal.msgError(res.msg);
                this.$refs.imageUpload.handleRemove(file);
                this.uploadedSuccessfully();
            }
        },
        // 删除图片
        handleDelete (file) {
            const findex = this.fileList.map(f => f.name).indexOf(file.name);
            if (findex > -1) {
                let ossId = this.fileList[findex].ossId;
                delOss(ossId);
                this.fileList.splice(findex, 1);
                this.$emit("input", this.listToString(this.fileList));
            }
        },
        // 上传失败
        handleUploadError () {
            this.$modal.msgError("上传图片失败，请重试");
            this.$modal.closeLoading();
        },
        // 上传结束处理
        uploadedSuccessfully () {
            if (this.number > 0 && this.uploadList.length === this.number) {
                this.fileList = this.fileList.concat(this.uploadList);
                this.uploadList = [];
                this.number = 0;
                this.$emit("input", this.listToString(this.fileList));
                this.$modal.closeLoading();
            }
        },
        // 预览
        handlePictureCardPreview (file) {
            this.dialogImageUrl = file.url;
            this.dialogVisible = true;
        },
        // 对象转成指定字符串分隔
        listToString (list, separator) {
            let strs = "";
            separator = separator || ",";
            for (let i in list) {
                if (list[i].ossId) {
                    strs += list[i].ossId + separator;
                }
            }
            return strs != "" ? strs.substr(0, strs.length - 1) : "";
        },
    }
};
</script>
<style lang="scss" scoped>
// .el-upload--picture-card 控制加号部分
::v-deep.hide .el-upload--picture-card {
    display: none;
}

// 去掉动画效果
::v-deep .el-list-enter-active,
::v-deep .el-list-leave-active {
    transition: all 0s;
}

::v-deep .el-list-enter, .el-list-leave-active {
    opacity: 0;
    transform: translateY(0);
}
</style>

